Process for producing flexible organic-inorganic laminates

ABSTRACT

Processes for producing flexible organic-inorganic laminates by atomic layer deposition are described, as well as barrier films comprising flexible organic-inorganic laminates. In particular, a process for producing a laminate including (a) depositing an inorganic layer by an atomic layer deposition process, and (b) depositing an organic layer comprising selenium by a molecular layer deposition process is provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase Application ofPCT/EP2015/080988, filed Dec. 22, 2015, which claims the benefit ofpriority to European Patent Application No. 15151839.6, filed Jan. 20,2015, and to European Patent Application No. 15161121.7, filed Mar. 26,2015, the entire contents of which are hereby incorporated by referenceherein.

BACKGROUND

The present invention is in the field of processes for producingflexible organic-inorganic laminates as well as barrier films comprisingflexible organic-inorganic laminates by atomic layer deposition.

Electronic devices need efficient encapsulation and passivation due totheir high sensitivity to moisture and oxygen. Typically, inorganicmaterials such as oxides, nitrides, carbides or glass are used asbarrier material as they show excellent moisture and oxygen barrierproperties. However, inorganic materials strongly limit the form factorof electronic devices due to their rigidity. Furthermore, the fragilityof e.g. large glass sheets makes production processes difficult andexpensive. Electronic devices containing materials such as glass areprone to breakage upon mechanical stress.

WO 2009/002 892 A1 discloses coatings having inorganic layers andflexibilizing polymeric layers. However, the barrier properties arestill insufficient for some applications.

DESCRIPTION

It was an objective of the present invention to provide a process forproducing films with high water and oxygen barrier properties. At thesame time it was aimed at providing a process for producing films whichretain their barrier properties under high mechanical stress. A furtherobjective was to provide a process for producing films with highstability against degradation in a humid atmosphere at elevatedtemperatures.

The objectives were achieved by a process for producing an laminatecomprising

(a) depositing an inorganic layer by an atomic layer deposition process,and

(b) depositing an organic layer comprising selenium by a molecular layerdeposition process.

The present invention further relates to a laminate comprising

(a) an inorganic layer and

(b) a selenium-comprising organic layer.

The present invention further relates to a barrier film comprising thelaminate according to the present invention.

The present invention further relates to the use of the barrier filmaccording to the present invention for encapsulation, packaging, orpassivation.

The present invention further relates to an electronic device comprisingthe barrier film according to the present invention.

Preferred embodiments of the present invention can be found in thedescription and the claims. Combinations of different embodiments fallwithin the scope of the current invention.

A laminate in the context of the present invention is a product in whichat least two layers of a different chemical composition are in closecontact to each other. Unless indicated otherwise, there is generally noparticular restriction to the size, the composition of each layer, orthe strength with which the layers are held together.

Inorganic in the context of the present invention refers to materialswhich contain at least 1 wt.-% of at least one metal or semimetal,preferably at least 2 wt.-%, more preferably at least 5 wt.-%, inparticular at least 10 wt.-%. Organic in the context of the presentinvention refers to materials which contain more than 99 wt.-% ofnonmetals, preferably more than 99.5 wt.-%, in particular completely oressentially completely. It is even more preferable that the nonmetalsare C, H, O, N, S, Se and/or P.

Atomic layer deposition (ALD) is a technique in which a series ofself-limiting surface reactions are conducted which builds up conformalcoatings of precise thickness depending on the number of self-limitingreactions performed. Typically the surface reaction takes place uponadsorption of a precursor from the gaseous state to the substrate. Whenall surface sites of the substrate are occupied, no further precursoradsorbs to the substrate making the reaction self-limiting. Afterremoval of excess precursor the deposited layer is treated eitherchemically or physically which allows the subsequent deposition offurther precursor. A sequence comprising such deposition and treatmentis usually referred to as a cycle in the ALD process. The ALD process isdescribed in detail by George (Chemical Reviews 110 (2010), 111-131). Iforganic molecules are deposited in an ALD process, such a process issometimes referred to as molecular layer deposition process (MLD).

The process according to the present invention comprises depositing aninorganic layer by an atomic layer deposition process. The inorganiclayer is deposited by any number of atomic layer deposition cycles, forexample 1 to 1000, preferably 2 to 200, more preferably 4 to 60, inparticular 5 to 30.

A cycle in an ALD process to form an inorganic layer typically comprisesbringing a metal- or semimetal-containing compound or mixtures thereofinto the gaseous state and depositing it from the gaseous state onto asubstrate. In the following the term “metal or semimetal or mixturesthereof” is abbreviated by “(semi)metal”. Bringing the(semi)metal-containing compound to the gaseous state can be achieved byheating it to elevated temperatures. In any case a temperature below thedecomposition temperature of the (semi)metal-containing compound has tobe chosen. Preferably, the heating temperature ranges from slightlyabove room temperature to 300° C., more preferably from 30° C. to 250°C., even more preferably from 40° C. to 200° C., in particular from 50°C. to 150° C. Alternatively, an inert gas such as nitrogen or argon canbe purged through the (semi)metal-containing compound. In this way theinert gas is saturated with (semi)metal-containing compound in thegaseous state corresponding to the vapor pressure of the(semi)metal-containing compound.

Metals in the metal-containing compound are Li, Be, Na, Mg, Al, K, Ca,Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Tc,Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb,Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, TI, Bi.Semimetals in the semimetal-containing compound are B, Si, As, Ge, Sb.Preferred (semi)metals are B, Al, Si, Ti, Zn, Y, Zr, La, in particularAl.

Any (semi)metal-containing compound which can be brought into thegaseous state is suitable. Preferably, the (semi)metal-containingcompound is a (semi)metal organic compound. These compounds includealkyl (semi)metals such as dimethyl zinc, trimethylaluminum or dibutyltin; (semi)metal alkoxylates such as tetramethoxy silicon ortetra-isopropoxy zirconium; cyclopentadiene adducts like ferrocene ortitanocene; (semi)metal carbenes such as tantalum-pentane-opentylat orbisimidazolidinylenrutheniumchloride; (semi)metal halogenides such asgermanium tetrabromide or titanium tetrachloride; carbon monoxidecomplexes like chromium hexacarbonyl or nickel tetracarbonyl. Morepreferably, the (semi)metal-containing compound is an alkyl (semi)metal,in particular a C₁ to C₄ alkyl (semi)metal.

It is possible to use more than one (semi)metal-containing compound. Inthis way it is possible to produce inorganic layers comprising forexample mixed (semi)metal oxides such as tin-zinc oxide orbarium-titanium oxides.

Preferably, a second (semi)metal-containing compound is present at 1 to30 mol-% with respect to the total molar amount of(semi)metal-containing compound, more preferably at 2 to 15 mol-%. Inthis case, (semi)metal-doped inorganic layers are accessible, forexample aluminum-doped zinc oxide, tin-doped indium oxide, orantimony-doped tin oxide. Alternatively, in order to obtainhalogen-doped inorganic layers it is possible to use a halogen- and(semi)metal-containing compound or a halogen-containing compound inaddition to the (semi)metal-containing compound preferably in an amountof 1 to 30 mol-% with respect to the total molar amount of(semi)metal-containing compound and halogen-containing compound, morepreferably of 2 to 15 mol-%. Examples for such halogen-containingcompounds are chlorine gas, ammonium fluoride or tin tetrachloride.

A cycle in an ALD process to form an inorganic layer typically furthercomprises the decomposition of the (semi)metal-containing compound afterit is deposited onto a substrate. The decomposition can be effected invarious ways. The temperature of the solid substrate can be increasedabove the decomposition temperature of the (semi)metal-containingcompound. Furthermore, it is possible to expose the deposited(semi)metal-containing compound to oxygen, ozone, a plasma like oxygenplasma, ammonia, oxidants like nitrous oxide or hydrogen peroxide,reducing agents like hydrogen, alcohols, hydrazine or hydroxylamine, orsolvents like water.

It is preferable to use oxidants, plasma or water to obtain a layer of a(semi)metal oxide. Exposure to water, an oxygen plasma or ozone ispreferred. Exposure to water is particularly preferred. If layers ofelemental (semi)metal are desired it is preferable to use reducingagents. For layers of (semi)metal nitrides it is preferable to useammonia or hydrazine.

A cycle in an ALD process to form an organic layer typically comprisesbringing a selenium-containing compound into the gaseous state anddepositing it from the gaseous state onto a substrate. The selenium inthe selenium-containing compound is preferably in the oxidation state−2, −1 or 0, which is minus two, minus one or zero, e.g. an organicselenol, an organic selenoether, or an organic diselenoether. An organicselenol is preferred. The selenium-containing compound can contain oneor more than one selenium atoms. Preferably, the selenium-containingcompound contains one or two selenium atoms. More preferably, theselenium-containing compound is an aromatic selenol. The selenol can bedirectly bound to the aromatic part of the molecule or via a linker suchas a methylene group, preferably it is directly bound to the aromaticgroup. The selenium-containing compound is even more preferably aselenophenol derivative. Preferably, the selenium-containing moleculefurther contains one or more hydroxyl groups. Some preferred examplesfor selenium-containing compounds are given below.

Particularly preferred are 4-hydroxyselenophenol (C-1) and(4-selanylphenyl)methanol (C-2). It is also possible to make the organiclayer with different organic molecules with the provision that at leastone organic molecule is selenium-containing.

Preferably, the selenium-containing compound contains at least twoselenium atoms, more preferably two selenium atoms. The selenium atomsin the selenium-containing compound are independent of each other partof functional groups as described above. Selenols are preferred,diselenols are more preferred. Preferably, two selenol groups areattached to an aromatic system, such as benzene, either directly or viaa linker such as a methylene group. Some preferred examples forselenium-containing compounds containing two selenium atoms are givenbelow.

It is also preferable that the selenium-containing compound contains oneselenium atom and one sulfur atom. More preferably, theselenium-containing compound is a selenol and a thiol, in particular theselenium-containing compound is a selenol and a thiol and furthercontains a hydroxy group. Some preferred examples of selenium-containingcompounds containing one selenium atom and one sulfur atom are givenbelow.

Preferably, the organic layer is made by one ALD cycle comprising aselenium-containing compound. However, it is also possible to run morethan one ALD cycles to form the organic layer. Often it is necessary toinclude the deposition of a linker compound in an ALD cycle for makingthe organic layer. Examples include phosgene, thionyl chloride, diaciddichlorides such as oxalyl chloride or diisocyanates such asethylenediisocyanate. It is also possible that an inorganic compound canform the linker such as alkyl (semi)metals, for exampletrimethylaluminum. In this case the organic layer also includes(semi)metals. Alternatively, after one ALD cycle to form the organiclayer treatment with water, oxygen or ozone can be done beforeperforming the next ALD cycle to form the organic layer.

The ALD process can be performed in a wide pressure range such as from5000 to 10⁻⁵ mbar. When the (semi)metal-containing compound or theselenium-containing compound is mixed with an inert gas, the pressure ispreferably around normal pressure such as 1500 to 500 mbar, morepreferably 1200 to 800 mbar. When the (semi)metal-containing compound orthe selenium-containing compound is not mixed with an inert gas thepressure depends on the vapor pressure of the (semi)metal-containingcompound or the selenium-containing compound. Often the pressure is thenfrom 100 to 10⁻³ mbar, more preferably from 10 to 0.1 mbar. In this caseit is preferable to run the process in an apparatus in which thepressure can be adjusted such as in a vacuum chamber.

The temperature for the ALD process is in the range of −20 to 500° C.,preferably 0 to 300° C., in particular 50 to 200° C. Typically, thesurface is exposed to the (semi)metal-containing compound or theselenium-containing compound in one ALD cycle for 1 ms to 30 s,preferably 10 ms to 5 s, in particular 50 ms to 1 s. It is preferable topurge the substrate with an inert gas in between exposing the surface tothe (semi)metal-containing compound or the selenium-containing compoundof different chemical structure, normally for 0.1 s to 10 min,preferably for 1 s to 3 min, in particular for 10 s to 1 min.

Preferably, in the process according to the present invention thesequence of depositing an inorganic layer and depositing aselenium-comprising organic layer is performed more than once,preferably at least 30 times, more preferably at least 100 times, inparticular at least 200 times. Preferably, this sequence is performed atmost 1000 times. The organic and inorganic layers can independent ofeach other be made by the same number of ALD cycles or by differentones. For example, one inorganic layer can be made by 4 ALD cycles whilea different one can be made by 8 ALD cycles. Preferably, all inorganiclayers are made with the same number of ALD cycles. More preferably, allinorganic layers are made with the same number of ALD cycles and allorganic layers are made by one ALD cycle.

Furthermore it is possible that different compounds are used forproducing different inorganic layers or for different organic layers.Preferably, all organic layers are produced with the same organiccompounds. Preferably, all inorganic layers are produced with the same(semi)metal-containing compound.

Preferably, the process according to the present invention is performedby passing the (semi)metal-containing compound and theselenium-containing compound in the gaseous state through separateorifices which are moved relative to the substrate. This means thateither the substrate is moved and the orifices are kept immobile or thesubstrate is kept immobile while the orifices are moved or both thesubstrate and the orifices are moved. Preferably the speed of motion isfrom 0.01 to 10 m/s, more preferably 0.02 to 1 m/s, in particular 0.05to 0.3 m/s. The orifices are arranged such that the(semi)metal-containing compound and selenium-containing compound hit thesurface of the substrate in the order as described for the processabove. Preferably, at least two orifices through which a(semi)metal-containing compound is passed towards the surface arepresent to build up thicker layers containing the (semi)metal.Decomposition of the (semi)metal-containing compound is preferablyeffected by an orifice through which a decomposition material, such aswater, is passed towards the surface of the substrate. In order to avoidreactions in the gas phase it is preferred to place orifices throughwhich an inert gas, such as nitrogen or argon, are passed towards thesurface of the substrate.

When performing the process by passing the (semi)metal-containingcompound and the selenium-containing compound through separate orificesthe pressure at the substrate is preferably 100 to 5000 mbar, morepreferably 500 to 1500 mbar, in particular 800 to 1200 mbar, such asatmospheric pressure. Alternatively, however, it is possible to uselower pressures as described above if the apparatus can be evacuated.

Preferably the orifices are mounted on a rotating drum around which thesubstrate is placed, preferably moved. Such an apparatus is described inWO 2011/099 858 A1. In case the substrate is flexible anorganic-inorganic substrate can thus be deposited on a large substratein a so-called roll-to-roll process.

The process according to the present invention yields laminates with lowpermeability for small molecules like water and oxygen and with highflexibility. Therefore, the present invention also relates to laminatescomprising an inorganic layer and a selenium-comprising organic layer. Agood measure for the permeability for small molecules is the water vaportransmission rate (WVTR). It is preferably measured by evaporating anarray of calcium dots onto the laminates and depositing another laminateon top of the calcium dots. These samples are then exposed to warm humidair, for example at 30 to 100° C. at 30 to 90% relative humidity,preferably at 60 to 85° C. at 70 to 90% relative humidity, for exampleat 60° C. and 90% relative humidity or 85° C. and 85% relative humidity.This exposure usually takes at least 100 hours, preferably at least 200hours, in particular at least 300 hours. Normally, the exposure does nottake more than 1000 hours. The number of calcium dots which have turnedtransparent is used to calculate the WVTR as described by Paetzold etal. (Review of Scientific Instruments 74 (2003) 5147-5150). Generally, alaminate is regarded as having a low permeability for small molecules ifthe WVTR is smaller than 10⁻² g/m²d, preferably 10⁻⁴ g/m²d, morepreferably 10⁻⁵ g/m²d, in particular 10⁻⁶ g/m²d.

A suitable method of measuring the flexibility of the laminate is tobend the laminate containing calcium dots and a second laminate on topas described above several times, for example 100 times, around acylindrically shaped object with a radius of 0.1 to 10 cm, preferably0.1 to 2 cm and measure the WVTR rate afterwards as described above. Thelaminate is regarded as having high flexibility if the WVTR is not morethan 1000 times higher in comparison to the respective laminate beforebending, preferably not more than 100 times higher, in particular notmore than 10 times higher.

Preferably, the inorganic layer has a thickness 0.4 to 15 nm, morepreferably 0.5 to 5 nm, in particular 0.6 to 3 nm. Theselenium-comprising organic layer preferably has a thickness of 0.1 to10 nm, more preferably of 0.2 to 5 nm, in particular 0.3 to 3 nm, suchas 0.4 to 1 nm. The thickness of the layers is typically measured byX-ray diffraction such as wide-angle X-ray diffraction (WAXD),preferably with a synchrotron as X-ray source.

The inorganic layer can be chosen from a wide variety of compounds.These include inorganic oxides, inorganic nitrides, inorganic carbides,perovskites, garnets, pyrochlors, transparent conductors and II-VIcompounds. Inorganic oxides are preferred.

Examples for inorganic oxides including earth alkaline metal oxides suchas Be), MgO, CaO, SrO, BaO; main group metal oxides such as Al₂O₃, SiO₂,Ga₂O₃, GeO₂, In₂O₃, SnO₂, Tl₂O, PbO, PbO₂, Bi₂O₃; transition metaloxides such as Sc₂O₃, TiO₂, V₂O₅, CrO₂, Cr₂O₃, MnO, Mn₂O₃, FeO, Fe₃O₄,Fe₂O₃, CoO, Co₂O₃, NiO, Ni₂O₃, Cu₂O, CuO, ZnO, Y₂O₃, ZrO₂, Nb₂O₅, MoO,MoO₂, RuO₂, Rh₂O, PdO, Ag₂O, CdO, HfO₂, Ta₂O₅, WO₃, ReO₃, OsO₄, IrO₂,PtO₂, AuO, Hg₂O; lanthanoid oxides such as La₂O₃Ce₂O₃, CeO₂, Pr₂O₃,Nd₂O₃, Pm₂O₃, Sm₂O₃, Eu₂O₃, Gd₂O₃, Tb₂O₃, Dy₂O₃, Ho₂O₃, Er₂O₃, Tm₂O₃,Yb₂O₃, Lu₂O₃. Preferred are B₂O₃, Al₂O₃, SiO₂, La₂O₃, Y₂O₃, ZnO, ZrO₂,in particular Al₂O₃. Often, oxides in thin layers according to thepresent invention are hydrated to some extent. These hydratesnevertheless count as oxides represented by a formula above in thecontext of the present invention. Alternatively, the oxide Al₂O₃, forexample, can be represented by the more general formula AlO_(x)(OH)_(y),wherein 0≤x≤1.5; 0≤y≤3 and 2 x+y=3, preferably 1≤x≤1.5; 0≤y≤1 and 2x+y=3.

Examples for inorganic nitrides include BN, AlN, Si₃N₄, Ti₃N₄, TaN, NbN,WN, MoN, GaN, Zr₃N₄, InN, and Hf₃N₄, preferably BN, AlN, Si₃N₄, Ti₃N₄,Zr₃N₄. Examples for inorganic carbides include B₄C₃, SiC, ZrC. Examplesfor perovskites include BaTiO₃, SrTiO₃, LaNiO₃, and LaCoO₃. Examples forgarnets include Fe₃Al₂(SiO₄)₃, Mg₃Al₂(SiO₄)₃, and Mn₃Al₂(SiO₄)₃.Examples for pyrochlores include La₂Zr₂O₇, Gd_(1.9)Ca_(0.1)Ti₂O_(6.9),Dy₂Ti₂O₇, and Y₂Mo₂O₇. Examples for transparent conductors includeSn-doped In₂O₃, Sb-doped SnO₂, F-doped SnO₂, Al-doped ZnO. Examples forII-VI compounds are ZnS, ZnSe, ZnTe, CaS, SrS, BaS, CdS, CdTe, CdSe.Furthermore, mixed oxides and/or nitrides are possible such as AlON,SiAlON.

Preferably, the laminate comprises at least two inorganic layers with aselenium-comprising organic layer in between. More preferably, thelaminate comprises alternatingly at least 30 inorganic and at least 30organic layers, even more preferably at least 100 inorganic and at least100 organic layers, in particular at least 200 inorganic and at least200 organic layers. Preferably, the laminate comprises not more than1000 inorganic and not more than 1000 organic layers. Alternatinglymeans that each two inorganic layers are separated by an organic layer.

Preferably the organic layer contains selenium in the oxidation state−2, −1 or 0, more preferably in the oxidation state −2 or −1. It ispossible that different selenium atoms in the organic layer are ofdifferent oxidation states. In this case it is preferable if the averageoxidation state of the selenium is 0 to −2. The oxidation state ofselenium in a laminate according to the present invention can bedetermined by the characteristic bands in an infrared (IR) spectrum ofthe laminate.

The laminate according to the present invention is particularly usefulfor making barrier films. Therefore the present invention furtherrelates to a barrier film comprising the laminate according to thepresent invention.

The barrier film according to the present invention typically furthercomprises a substrate. The substrate can be any solid material. Theseinclude for example metals, semimetals, oxides, nitrides, and polymers.It is also possible that the substrate is a mixture of differentmaterials. Examples for metals are aluminum, steel, zinc, and copper.Examples for semimetals are silicon, germanium, and gallium arsenide.Examples for oxides are silicon dioxide, titanium dioxide, and zincoxide. Examples for nitrides are silicon nitride, aluminum nitride,titanium nitride, and gallium nitride. Polymers are preferred. Polymersinclude polyesters such as polyethylene terephthalate (PET) orpolyethylene naphthalene-dicarboxylic acid (PEN); polyimides;polyacrylates such as poly methyl methacrylate (PMMA); polyacrylamides;polycarbonates such as poly(bisphenol) A carbonate); polyvinylalcoholand its derivatives like polyvinyl acetate or polyvinyl butyral;polyvinylchloride; polyolefins such as polyethylene (PE) orpolypropylene (PP); polycycloolefins such as polynorbornene;polyethersulphone; polyamides like polycaprolactam or poly(hexamethyleneadipic amide); cellulose derivatives such as hydroxyethyl cellulose,hydroxypropyl cellulose, methyl cellulose, methyl hydroxylpropylcellulose or nitrocellulose; polyurethanes; epoxy resins; melamineformaldehyde resins; phenol formaldehyde resins. Polymers includecopolymers such as poly(ethylene-co-norbornene) orpoly(ethylene-co-vinylacetate). Polyesters and polycycloolefins arepreferred.

The substrate can have any size and shape. Preferably the substrate is afilm. The thickness of the substrate film depends on the application. Ifthe barrier film is bent around a radius of more than 10 mm, thesubstrate film preferably has a thickness of 100 to 1000 μm, morepreferably 100 to 500 μm, for example 100 to 200 μm. If the barrier filmis bent with a radius of less than 10 mm the substrate film preferablyhas a thickness of 1 to 100 μm, more preferably 10 to 70 μm, such as 40to 60 μm.

The surface of the substrate is preferably of high planarity. Highplanarity in the context of the present invention means that the highestpoint on the surface is not more than 100 nm higher than the lowestpoint on the surface, preferably not more than 50 nm. The planarity canbe measured with atomic force microscopy, preferably in tapping mode.

Substrates are often not available with high planarity, e.g. due tosmall scratches, or particles such as dust adhered to their surface. Itis therefore preferred that the barrier film further comprises aplanarization layer to avoid damaging such as puncturing the laminate.More preferably the planarization layer is in between the substrate andthe laminate. In this case the planarization layer can additionallyserve to better hold together the substrate and the laminate,particularly upon bending or heating. Planarization layers can compriseorganic polymers such as acrylates or epoxy, ceramics such as carbides,e.g. SiC, or organic-inorganic hybrid materials such aspolyalkylsiloxanes. Organic polymers are preferred.

Often the planarization layer is made by depositing the material makingup the planarization layer on the substrate before applying thelaminate. In the case of organic polymers a liquid comprising a monomeris cast on the substrate and then cured, for example by heating or by UVinitiation. UV initiation is preferred, more preferably the liquidcomprising the monomer further comprises a curing aid such as afunctionalized benzophenone. Preferably the liquid comprising themonomer comprises a mixture of mono- and difunctional monomers such thatcross-linked organic polymers are obtained after curing. Planarizationlayers comprising ceramics are usually obtained by sputtering thematerial onto the substrate. Planarization layers comprisingorganic-inorganic hybrid materials can be obtained by casting a solutioncomprising an organic-inorganic precursor on the substrate, evaporatingthe solvent and condensing the organic-inorganic precursor, for exampleby heating. This process is often referred to as sol-gel process. Anexample for an organic-inorganic precursor is alkyl-trialkoxysilane.Preferably the precursor is functionalized with a UV curable side group,for example acrylate. In this way the organic-inorganic hybrid materialcan be cross-linked.

Preferably the material making up the planarization layer has a modulusof elasticity in between that of the substrate material and that of thelaminate, for example 10 to 30 GPa. The method of determining themodulus of elasticity is described in ISO 527-1 (Plastics—Determinationof tensile properties, 2012).

Preferably the barrier film according to the present invention furthercomprises a protective layer to avoid mechanical damaging of thelaminate, e.g. by scratching. The protective layer can for examplecomprise an epoxy resin. It is further possible that the protectivelayer is an adhesive which e.g. connects the laminate to an electronicdevice. It has surprisingly found out that a combination of the barrierfilm according to the present invention with a protective layer shows asynergistic effect with regard to the WVTR, i.e. the WVTR is lower thanone would expect when combining the barrier film and the protectivelayer.

Preferably the barrier film according to the present invention furthercomprises a getter material. This getter material binds small moleculeslike water or oxygen and thus decreases the permeability of the barrierfilm even further. Examples for getter materials are highly reactivemetals such as Ca or strongly water-absorbing oxides such as CaO orSiO₂.

The present invention further relates to the use of the barrier filmaccording to the present invention for encapsulation, packaging orpassivation. Any good which is sensitive to small molecules like wateror oxygen can be encapsulated, packed or passivated with the barrierfilms according to the present invention such as food, medicaments,reactive chemicals, batteries, or preferably electronic devices.Examples for electronic devices are field-effect transistors (FET),solar cells, light emitting diodes, sensors, or capacitors, inparticular if the active materials in the electronic devices are organicmolecules. The barrier film according to the invention can in additionbe used as electric insulator, for example as dielectric in atransistor.

With the process according to the present invention laminates areaccessible which have a high barrier against the diffusion of smallmolecules. These laminates maintain their high diffusion barrier uponbending. When using flexible substrates, flexible barrier films areaccessible with high diffusion barriers.

We claim:
 1. A process for producing a laminate, the process comprisinga sequence comprising: (a) depositing an inorganic layer by an atomiclayer deposition process; and (b) depositing an organic layer comprisingan aromatic selenol comprising one or more hydroxyl groups by amolecular layer deposition process, wherein the selenol is directlybound to the aromatic group; wherein the sequence is performed more thanonce, wherein the inorganic layer is deposited by 4 to 150 atomic layerdeposition cycles, and wherein each organic layer is deposited by onemolecular layer deposition cycle.
 2. The process according to claim 1wherein a diselenol is used in the molecular layer deposition process todeposit the organic layer.
 3. The process according to claim 1 whereinan Al-containing compound is used in the atomic layer deposition processto deposit the inorganic layer.